The database, formally called the Global Tailings Portal (GTP), was built by the group as part of the Investor Mining and Tailings Safety Initiative, which is led by the Church of England Pensions Board and the Swedish National Pension Funds' Council on Ethics, with support from the UN Environment Program (UNEP).
Users can view information on more than 1,900 tailings dams, categorised by location, company, dam type, height, volume and risk, among other factors.
GRID-Arendal officials said the database was not complete, so the amount of available information is likely to grow; some estimates show dam numbers exceeding 3,500 worldwide.
The database is publicly accessible anytime, and users can download data to their computers.
"Most of this information has never before been publicly available," according to programme leader for geological resources Kristina Thygesen.
"This database brings a new level of transparency to the mining industry, which will benefit regulators, institutional investors, scientific researchers, local communities, the media and the industry itself."
The portal project is a follow-up from UNEP and GRID-Arendal's 2017 report 'Mine Tailings Storage: Safety is No Accident'.